+*** Changes in GCC 3.4:
+
+* Changes in GCC 3.4 are described in 'gcc-3.4/changes.html'
+
+*** Changes in GCC 3.3:
+
+* The "new X = 3" extension has been removed; you must now use "new X(3)".
+
+* G++ no longer allows in-class initializations of static data members
+ that do not have arithmetic or enumeration type. For example:
+
+ struct S {
+ static const char* const p = "abc";
+ };
+
+ is no longer accepted.
+
+ Use the standards-conformant form:
+
+ struct S {
+ static const char* const p;
+ };
+
+ const char* const S::p = "abc";
+
+ instead.
+
+ (ISO C++ is even stricter; it does not allow in-class
+ initializations of floating-point types.)
+
*** Changes in GCC 3.1:
* -fhonor-std and -fno-honor-std have been removed. -fno-honor-std was
a workaround to allow std compliant code to work with the non-std
compliant libstdc++-v2. libstdc++-v3 is std compliant.
+* The C++ ABI has been fixed so that `void (A::*)() const' is mangled as
+ "M1AKFvvE", rather than "MK1AFvvE" as before. This change only affects
+ pointer to cv-qualified member function types.
+
* The C++ ABI has been changed to correctly handle this code:
-
+
struct A {
void operator delete[] (void *, size_t);
};
- struct B : public A {
+ struct B : public A {
};
new B[10];
The amount of storage allocated for the array will be greater than
it was in 3.0, in order to store the number of elements in the
array, so that the correct size can be passed to `operator delete[]'
- when the array is deleted. Previously, the value passed to
+ when the array is deleted. Previously, the value passed to
`operator delete[]' was unpredictable.
This change will only affect code that declares a two-argument
`operator delete[]' with a second parameter of type `size_t'
- in a base class, and does not override that definition in a
+ in a base class, and does not override that definition in a
derived class.
* The C++ ABI has been changed so that:
- struct A {
+ struct A {
void operator delete[] (void *, size_t);
void operator delete[] (void *);
};
* The C++ ABI has been changed so that when a parameter is passed by value,
any cleanup for that parameter is performed in the caller, as specified
- by the ia64 C++ ABI, rather than the called function as before.
+ by the ia64 C++ ABI, rather than the called function as before. As a
+ result, classes with a non-trivial destructor but a trivial copy
+ constructor will be passed and returned by invisible reference, rather
+ than by bitwise copy as before.
+
+* G++ now supports the "named return value optimization": for code like
+
+ A f () {
+ A a;
+ ...
+ return a;
+ }
+
+ G++ will allocate 'a' in the return value slot, so that the return
+ becomes a no-op. For this to work, all return statements in the function
+ must return the same variable.
*** Changes in GCC 3.0:
are those whose types involve non-type template arguments whose
mangled representations require more than one digit.
-* Support for assignment to `this' has been removed. This idiom
+* Support for assignment to `this' has been removed. This idiom
was used in the very early days of C++, before users were allowed
to overload `operator new'; it is no longer allowed by the C++
standard.
* G++ previously allowed `sizeof (X::Y)' where Y was a non-static
member of X, even if the `sizeof' expression occurred outside
- of a non-static member function of X (or one of its derived classes,
+ of a non-static member function of X (or one of its derived classes,
or a member-initializer for X or one of its derived classes.) This
extension has been removed.
-* G++ no longer allows you to overload the conditional operator (i.e.,
+* G++ no longer allows you to overload the conditional operator (i.e.,
the `?:' operator.)
* The "named return value" extension:
-
+
int f () return r { r = 3; }
has been deprecated, and will be removed in a future version of G++.
*** Changes in EGCS 1.1:
-* Namespaces are fully supported. The library has not yet been converted
+* Namespaces are fully supported. The library has not yet been converted
to use namespace std, however, and the old std-faking code is still on by
default. To turn it off, you can use -fhonor-std.
but not all, the compiler will tell you where you need to add
'typename'. For more information, see
- http://www.cygnus.com/misc/wp/dec96pub/template.html#temp.res
+ http://www.cygnus.com/misc/wp/dec96pub/template.html#temp.res
- + Guiding declarations are no longer supported. Function declarations,
+ + Guiding declarations are no longer supported. Function declarations,
including friend declarations, do not refer to template instantiations.
You can restore the old behavior with -fguiding-decls until you fix
your code.
+ Explicit instantiation of template constructors and destructors is
now supported. For instance:
- template A<int>::A(const A&);
+ template A<int>::A(const A&);
Still not supported:
converting from a bound member function pointer to function
pointer).
- + A flag -Weffc++ has been added for violations of some of the style
+ + A flag -Weffc++ has been added for violations of some of the style
guidelines in Scott Meyers' _Effective C++_ books.
+ -Woverloaded-virtual now warns if a virtual function in a base
signatures are overridden) as it did before.
+ -Wall no longer implies -W. The new warning flag, -Wsign-compare,
- included in -Wall, warns about dangerous comparisons of signed and
- unsigned values. Only the flag is new; it was previously part of
- -W.
+ included in -Wall, warns about dangerous comparisons of signed and
+ unsigned values. Only the flag is new; it was previously part of
+ -W.
+ The new flag, -fno-weak, disables the use of weak symbols.
* __FUNCTION__ and __PRETTY_FUNCTION__ are now treated as variables by the
parser; previously they were treated as string constants. So code like
- `printf (__FUNCTION__ ": foo")' must be rewritten to
+ `printf (__FUNCTION__ ": foo")' must be rewritten to
`printf ("%s: foo", __FUNCTION__)'. This is necessary for templates.
* local static variables in extern inline functions will be shared between
translation units.
-* -fvtable-thunks is supported for all targets, and is the default for
+* -fvtable-thunks is supported for all targets, and is the default for
Linux with glibc 2.x (also called libc 6.x).
* bool is now always the same size as another built-in type. Previously,
supported. For instance:
struct A {
- struct B;
- B* bp;
+ struct B;
+ B* bp;
};
struct A::B {
- int member;
+ int member;
};
* On the HPPA, some classes that do not define a copy constructor
* Joe Buck <jbuck@synopsys.com>, the maintainer of the g++ FAQ.
* Brendan Kehoe <brendan@cygnus.com>, who coordinates testing of g++.
* Jason Merrill <jason@cygnus.com>, the g++ maintainer.
-* Mark Mitchell <mmitchell@usa.net>, who implemented member function
+* Mark Mitchell <mmitchell@usa.net>, who implemented member function
templates and explicit qualification of function templates.
* Mike Stump <mrs@wrs.com>, the previous g++ maintainer, who did most of
the exception handling work.
+
+\f
+Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003,
+2005 Free Software Foundation, Inc.
+
+Copying and distribution of this file, with or without modification,
+are permitted in any medium without royalty provided the copyright
+notice and this notice are preserved.
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